Adjustable bending brake with work clamp latching means



July 8, 1952 ADJUSTABLE BENDING BRAKE WITH W Filed Jan. 20, 1948 w. c. TlFF. T ETAL 2,602,484

ORK CLAMP LATCHING MEANS 4 Shets-Sheet l 132 William 0. rm;

Jacob f. Kreisslg mmvroxs July 8, 1952 w. c. TlFFT ETAL 2,

ADJUSTABLE BENDING BRAKE WITH WORK CLAMP LATCHING MEANS Filed Jan. 20, 1948 4 Sheets-Sheet 2 Fig.5.

/ William 6.

July 8, 1952 w. c. TlFFT ETAL ADJUSTABLE BENDING BRAKE WITH WORK CLAMP LATCHING MEANS Filed Jan. 20, 1948 4 Sheets-Sheet 3 m ww M e m t.. m m@ If. Ha wJ INVENTORS y 8, 1952 w. c. TlFFT ET AL 2,602,484

ADJUSTABLE BENDING BRAKE WITH WORK CLAMP LATCHING MEANS Filed Jan. 20, 1948 4 Sheets-Sheet 4 William 6. Tiff; Jacab f. Kreissig INVENTORS 62 46 Fig. 8.

\ use I I68 26 I06 20 24 2 64 52 V ea 86- 132 I22 94 90 '4 a4 9a 16 74 )4 15 Fig. 9.

/38 42 I58 lxluxq uvfi Patented July 8, 1352 ADJUSTABLE William 0. Tifft,

BENDING BRAKE WITH WORK. AMP LATCHING IVIEANS Seymour, Conn, and Jacob F.

Kreissig, Frederick, 'Md., assignors to Frederick Iron and Steel, Inc., Frederick, Md., a corporation of Maryland Application January 20, 1948, Serial No.

7 Claims. (01. 153-16) This invention comprises novel and useful improvements in an adjustable sheet metal bar folder and has for its primary object the provision of a machine for forming marginal .folds, bends or flanges in metal sheets, of predetermined widths and through various arcsof bending.

An important object of this invention resides in providing an apparatus for bending metal sheets to form marginal flanges of predetermined and widely varied width.

A further object is to provide an apparatus in accordance with the preceding object which is capable of forming bends of any predetermined extent including substantially complete 360 bend.

Still another important object of the invention resides in the provision of an apparatus which automatically and positively clamps the sheet to be bent to the anvil before the application of any substantial bending movement thereto; andwhich automatically releases the clamping action as the folder is returned to its inoperative position.

A still further object of the invention, in conformity with the preceding objects, is to provide an apparatus having margin determining means for positively limiting the width of the margin of a sheet to be bent and which is incapable of interference with or of hindrance'by the clamping means. I I

Still. another important obj ectv of the invention is to provide thicknesses for bending.

Yet another important object of the invention resides in providing an anvil, a folding carriage, clamping means for securing a sheet to the anvil, latch means for positively locking the clamping means into, clamped position, together with automatic means for controlling the clamping means and the latching means in. synchronized an apparatus which is easily adjustable to accommodate sheets of difierent' 2 r to be'specifically enumerated herein, resides in the provision of an apparatusas set forth in the preceding objects which shallbe of compact construction, durable and emcient, and with all of relatively light weight, portable andinexpensive. These, together with various ancillary objects of the invention which will later become apparent as the following description proceeds, are attained by this device, a preferred embodiment of which has been illustrated by way of example only in the accompanying drawings, wherein:

Figure l is a perspective view of the rear of the machine; 7 a Figure 2 is a perspective view of the front of the machine, with the carriage in its raised posi: tion for bending a sheet of metal;

Figure 3 is a perspective view of the sheet clamping means forming a part of the invenmachine, parts being broken away,

tion, shown detached from the machine;

Figure 4 is a vertical transverse sectional view through the machine, parts being shown in elevation, the mechanism being shown in its rest position and is taken substantially upon the plane of the section line 4-4 of Figure 1;

Figure 5 is a vertical sectional view through the taken substantially upon the plane of the section line 5-5 of Figure 1, the parts being in they position shown inFiguree;

Figure 6 is a vertical sectional view through the machine illustrating the operation of certain parts thereof, with the movable jaw illustarted in its closed position and the latching means engaged therewith; V

Figure '7 is an end elevational view of the device, parts being broken away and alternative positions of a stop means being indicated in dotted lines;

Figure 8 is a vertical transverse sectional view through the machine, illustrating its use in forming a bend in a sheet of metal; and,

Figure 9 is ahorizontal sectional detail view, illustrating the construction of an adjusting mechanism for regulating the amount of bending performed by the machine, and is taken substan- V tially upon the plane of the section line 9-9 of Figure 7.

In order'that the purposes, construction and advantages of this machine may be more readily understood, it is here notedithat it is frequently necessary -to form marginal bends, folds or flanges upon the edges of sheet metal strips for various purposes such as to secure marginal wires orcablesthereto; to provide flanges at Various angles to the sheet for a multitude of may be quickly set to elfect bending movements throughout various predetermined Hancuate extent. It is also highly desirable that.:clamping means shall be provided for rigidly securing the sheet to be bent to the anvil nf the :machine, and that there shall be no 'id'angernfvzslippage of this clamping means; and -ye't' tha't the cl-ain'ping means shall be automatically released in returning the operating part v:nfthe .,:machine lto its original or rest position.

Moreover, it is highly essential that the stop mechanism for regulating and determining the width:of' theimarginallzpnrtion of "the sheetrto be folded shall have .trnezrectilinear motion 'to main- ,tain' a parallel :relation of the :fold --:of :the :sheet to its marginal edge :throughout all positions :of adjustment. V

The present 'invention'fefiiciently attains Zthe above objects and the above requisites by :providingarstationary ianv'il about'which a sheet is tobeibent, and zproviding n rswin'ging -nr gpi votal carriage ff or conveying izheunain portion ;of the sheet aboutithezanviliinran azrcuate movement; by providingtaremovable chimpingiawfor engaging the marginal edge of the sheet and affixing the same rigidly tolithe (anvil; :by-qprovidingrspring means for normally rin'g'mgithe movablejiaw into its clamping positionianil bysprovidingautoma-tic means :for retracting the movable ijaW when the *bending carfiage sis retin'ned' to isubstantia-lly "its original or IGStipOSitiOlI; by providing an auto' matic latch meansforpositivlylocking theimov- "a'b le j aw into its Jclamping ,position: at the :begin- =1iing f the-bendingzoperatlomwhich latchsmeans is automaticall withdrawn immediatelymriortc the releasing of 'the movalble jaw by the carriage return movement. 'i-Ihereiisiurtherprovided a slidably adj ustableifinger assembly constituting ra stop for engagement .by .the marginal edge :of 1a sheet for thusidetemiining fthe'width of the flange to be folded on the edge of. the sheetj-whicH-stop is positively "guided :for .imovement to and irom the bending carriage sand is :at :all times ,:-parall'e;l with the bending edge. of the anvil.

' Referring 'now more spectfically liDlthB accompanying drawings, wherein likeinumerals :desig- 'nate similar :parts ithroug'hout'sthe various views, there is d'isclosediby wvayfoflexample ofzt'he principles of-th'e inventionflbut in 110 waynf-theslimitation thereof, a satisfactory embodimentuo'f a mechanism constructed iniaccordance with the foregoing :obj ectarmuisites andzadvantages.

Frame constructiunro) t the'mn'c'hme hereinafter set forth. The frame includes end walls 1' 2 and-abottom plate, bed or base l 4. Suitable'lugs or'bra'ckets 'I'B comprisemeans for supporting the frame and for securing the same-to any satisfactory support, "it being here e'm'ph'albevelled nose .stitutes thesurfaceiaibout which a sheet of metal 'is'toibe-folded. Asshown in Figure 1, the anvil 4 sized that the machine is intended to be of a portable nature.

The frame is further provided with a closed vertical back wall I8 and a top wall 20, which, as shown :best in Figures 4, and 8, is provided with -'a longitudinally :extendingjrecess' torsea't 22 for receiving an anv'il*24 thereon. "This anvilis preferably provided with a forwardly extending 26 forming a knife edge and conis detachably secured to the top wall 20 as by means :of .a,pl uralit :o'f fastening bolts 28, wherebythe-anvil'ispositioned for ready removal from the :device fonany necessary servicing, or for replacement"by'asu'bstitute anvil of any desired shapezor -contounas when forming bends having various predetermined characteristics.

As shown best in Figure 2, end walls H are provided with laterally extending bosses 30 at 'thil'ZUDlIEIIEDfiSLQIHd reanwardly of the end'walls 12 which :bosses are drilled :or :apertured to pro- .vide l'j'ournall receiving axle pins 32 byimeans of which .the :carriage assembly iindicated generally :at41is 'hinge'dlyand :pivotallymounted upon the frame nftthe machine. iAs-lmay bebestseen by fliignres 54, 2'5 I-and i6, the frame lfitis thus open :ai' its frontxand 'be'lowfth'e'ianvil 24 forthereceptiOIiiOf :a :mechanism to be'asubsequently set forth, this opening extending longitudinally of the frame between .the "two end .plates 12 thereof, whileithe .Lframe iisiurth'er provided adj acent its reartwall "with achamb'er ripening upwardly from the bottomsurface ofith'elbe'd plate 14, this chamber being indicated at 84.

The carriage assembly The carriage assembly '34 as shown FigureJZ is "of somewhat greater length than the; frame member "f0 and is provided at its extremities with laterally extending lugs 356 :which embrace the end walls F2 and by meansof'whi'ch the carriage assembly is pivoted to the axle pins "32. These axle pins "are rigi'dlyattached to the ;lugs"36, and extend through thebosses 3B, andfhave a pair of clamp operatingeams 3,8"ri'gidly'fastened to the inner ends of the' p'ins 3? wherebyth'ese cams are rotated as the- "carriage assembly "is "pivotally raised'orlowered. V

At each end, the carriage assemblyiis provided "with enlarged handlesockets 4!), either of which may detachalaly receive an operating handle 42, by means of which the carriage assembly'may be pivoted about the axle pins32 for raisin and lowering of the-same as set "forth hereinafter.

As shown best in'FigureB, each of the handle sockets "4'9 has pivoted thereto as by fastening screws-'44, a pair of arms 46 which at'their inner extremities support the transversely extending folder bar 48, having a .fiatfuppel surface 50 which asshown in "Figure *5,is disposed in a plane which is substantially parallel to 'theiplane'of the upper surface of the tapered portion 26 of the anvilfl. J'ournaled in thecarriage assembly 34, and extending through one of the end lugs 36 thereof, is a longi'tudinal-ly extending shaft 52 providedwitha knurled operating head 54 on the exposed-end-thereof. This'shaft is provided with a plurality of eccentrically disposed operating 'cains-or eoc'entrics b6 which are engagab'le with depen'ding operati-ng lugs 58 carried by thefolder bar 48, whereby upon rotation of'the shaft, the cam members cause an oscillation of the folder bar about its pivot point 44. One or more journals .60 are provided in the carriage assembly to provide bearings for the normally upright wall subsequently become apparent.

the shaft-52, which journals may be of any suitable and desired construction. Preferably, a lock screw '62 havinga knurled head to provide a fingergrip portion, extends through of the carriage 34, and has its end disposed for engagement with the shaft 52, whereby thelatter may be locked in any i desired position of adjustinent. Thus, by releas-' ing the said screw 62, the adjusting shaft 52 may be rotated by the thumb grip portion 56, causing the cams 56 to raise orlower the folder bar 28 relative to the knife edge portion 26 of the'anvil. This adjustment is for the purpose of accommo= dating different thicknesses of sheet metal which it is desiredto bend in the device, and also for regulating the radius of bend within the range of adjustment as set forth hereinafter. 1

Stop lugs are formed upon the inner edge of the carriage assembly 34, for abuttin engagement with the edge of the bottom plate M when the carriage is in its idle or rest position, as shown in Figure 5. These lugs thus serve to support the carriage in its rest position while a sheet of material is applied or removed from the device as set forth hereinafter.

As will be further apparent from Figures Zand 6, the carriage is provided with a plurality of screw threaded bolts or studs 66, which extend through the carriage and protrude from both the inner and outer surfaces thereof, these screw 1 threaded members being provided with lock nuts 88, whereby the studs or bolts may be adjustabiy protruded from'the inner surface of the carriage member and locked in adjusted position purpose which will be later apparent.

Movable clamp jaw assembly Pivotally secured to the frame it! inthe above mentioned cavity or recess in the front wall of the frame, is a movable clamp jaw it which as shown in Figures 2' and 5, is a flat bar extende ing substantially the entire length of the space between the two end walls I2. of the frame It, and which is pivotally mounted therein for oscillatory movement into and out of clamping engagement with the lower surface of the knife portion 26 of the anvil 24.

This movable clamp jaw comprises means for releasably securing the edge of a sheet of metal which it is desired to bend, to the undersurface of the anvil, whereby the remainder of the sheet may be bent about crease or fold. V

The upper or clamping surface of the movable jaw'is provided with a plurality of notches l2 providing clearance for a purpose which will As shownmost clearly in Figures 2, 5 and 8, a plurality of coil springs 14 are seated upon the bed plate I4 and at their upper ends are seated in sockets 16 formed in the lower surface of the movable jaw Ill. lTnese springs normally urge and biasthe clamp jaw into its upper and closedposition against the under resiliently clamping a metal sheettherebetween. A pair of support arms 18 (see Figure 6) are integrally formed and extend rearwardly from the movable jaw, for supporting the jaw for'pivotal movement about a fulcrum pin 89 which is suitably mounted in the above mentioned cavity or chamber 84 in the frame Ill. These support arms 18 extend through slots 82 in the frame H1, these slots providing the necessary clearance to permit the oscillation of the support arms '18 about the pins 8!). Extending axially from the the knife edge 25 to form the side of the anvil 24, thereby lower end of the movable law It, are a pair "of pintles 86 upon which are rotatably mounted a pair of rollers 88"whlchrar'e' positioned for engagement byv the operating cam 38 above-mentioned. 'It will thus be seenfrom Figure 6 that as the carriagetd is rotated about its axle pins, the cams 38 willbe likewise rotated toselectively engage or withdrawthe cam surface from the rollersst, thereby depressing the movable jaw Ill against the action of the-closing springs '54, or Obviously, the cams'35 will be appropriately positionedupon the axleshaft 32 to-cause the appropriately timed release of the movable jaw whereby the-springs lil may close the same? and the correspondingly timed engagement of the roller by the cams 38 whereby the latter upon predetermined opening movefor a ment of the carriage will force the jaw to its open position against the action of theclosing springs l'. v

It will thus be seen that various and automatic and predetermined timed operating connections between the" carriage 34 and the clamping jaw 10, are provided whereby the single movement of the carriage will serve to first release the jaw and permit the same to yieldingly clamp apiece of sheet metal-between the movable jaw and the anvil, and upon subsequent movement of the carriage will then apply'a bending movement to the sheetto cause the desired marginal flange or fold thereon.- I Y Y Jaw latching'assembly In order to insure that the movable jaw when once closed upon a sheet of metal will not be onintentionally opened by the force applied thereto as the metal is bent by the continued move ment' of the carriage, there is provided al'latch means for positively locking the jaw irito'flits closed position, this latch means being automatically controlled by the position of the carriage. For this purpose'the lower surface of the movable jaw is provided with a plurality of cam surfaces which are engageable by the correspondingly shaped inclined surfacesof wedges 32 formed upon latch pins 94 and slidable transversely of the frame and jaw. These pins 9A are slidably received in guide bosses *96 carried by the frame and at their latching ends extend for wardly of the frame for engagement by the above mentioned adjusting screws fiiiwhile their other extremities extend into the chamber 84 which provides clearance for the movement of the latch pins. A coiled spring 58 surrounds the latch pin and bears against the above mentioned bosses 96, and against the rear surface of the wedge 9.2, to thereby yieldingly urge the latch pins and wedges into their operative or latching position, at which time the inclined surface of the wedge 92 will rest upon and bear upwardly against the inclined cam surfaces 90 of the movable jaw.

From the foregoing, it will be seen that as soon as the movable jaw is moved upwardly in position'to clear the forward end of the wedges 92, the latter will be urged by the springs 98 into wedging and locking action beneath the '7 as shownin Figure :5, the latch pins. are .held .in their releasedrgposition. against-the action of the springs 198 bysengagementof the latch screws 6'6, :during which position, the stop .lugsfits-are engaging therorward edge :of the :bed plate ;I4-as .shownin Figure :5. v.Atthereame time, the'cam 3:8 haszenga-ged the rollers .88, and has. urged the movable jaw .10 into its lowermost position, "against the action of the .closingxspring I4, whereby there is .aclearance between the topper end nf the movable jaw III-and the lower-surface .of the "anvil .124, ,as shown in-.Figure .5, :and wherebya metal. sheet .may be inserted :between .the anvil and movable jaw. Asethe-carriage istnownnoved upwardly by the handle 42,. the adjusting bolts 166 are withdrawn from the end for z-the latch pins Bland the cam .38 :begins to withdraw from the .anllerBB .asshown in Figure 6. .This'withdrawal of'ethe cam .fIO-IITWHB roller permits the spring 14 to begin to raise the movable jaw 10 .iintil the latter-is resiliently clamped upona sheet iofz-metal placed thereon. As soon as theamovablejawihas raised .a sufllc-ient distance, the wedges -52 are 'driven therebeneath by-the springs -36, andat this -point return movement :of the jaw :is impossible until these locking wedges are positively released by the dow-nward movement :of 1711612311- rings: at engagement of the locking "bolts 65. Further upward movement of the carriage snow raises .the bodyeoi the metal sheet, causing a bend about the knife edge 26, as the folder margin of the metal sheet is clamped to the undersurface of the anvil. 'The extent of this bend will of course depend upon the amount of angular 5T0- tationimparted :to .the carriageBB by rotation of the same about its .aXle pins .32 by the handle 4'2.

n the releasing or return .movement of the carriage, to .itslower or restgposition, the adj-11sting screws 66 "first engage the latch pin BLand force the withdrawal of the same .i-rom beneath the movablejaw; and thereafter the cam :38 :engages'the'roller 88, .thusldepressingthe movable jaw against the spring "M.

Stopfinger assembly .In order .to provide even margins or flanges 'on thev sheet to be folded, *an-adjustablestop istnecessary to properly position the finargina'l .edge "of the metal sheet in the device. bly, which is-shown in its entirety in 13, and of which structural .-details are disc-losedfin Figures l, 5 and 3 in -.difier.ent positions of adjustment, consists of aifinger assemblysirame *Illll preferably comprising a flat; plate disposed longitudinally .of the :cav-ity in the :iront wall of the .frame I0, and positioned-behind the movable; jaw 111. ..At its upper extremity the assembly frame I08 is provided with bifurcated upwardly extendingllugs I02 between whichbiflurcations are received the rearwardly extending-ledge lugs W4 of the .fi-nger bar 106 which is pivoted thereto as by pins M33. The plate IIJI) is positioned generally vertical, while-thefingerbar I06 andtthe fingers carried thereby are positioned "generally horizontal.

Spring means such as. a resilient metallichstrip I10 is securedito the irame \I60 and against finger bar I05, .for resiliently urging the finger bar and the fingers thereby upwardly about their fulcrum or pivot pins 103. These fingerstindicated generally by .the numeral H2, preferably comprise forwardly extending rods H4, whose outermost. extremities are upward-1y turned .as at H6. The extremitiesl I are .preier'a'bly-posi- This stop 'assem- 78 rtionediin averti'oal plane which .is parallel to that of the frame J00.

Secured to the ends of the bar I06 areindicators' 1 I8 cooperating with scales I64, see Figure 1, for indicatingthe spacing .of :the fingers I I2 from the foldingedge of the knife 26.

Secured centrally and extending rearwardlyof the iframe 1:10, is a tubular sleeve I 20 provided with :an internally threaded bore, which sleeve .is slidinglyireceived in a guide bore I22 see Figure 8, which guide bore communicates with themterior of the chamber 84 above mentioned. An adjusting screw I24 provided with an operating knob 126,,extends through the .rear wall I 8 of the framaand is screw threadedly engaged in the. bore of the sleeve I20, whereby the sleeve and the attached frame Hill with the finger bar, may be moved rearwardly .for adjusting the fingers with-respect to the knife edge.

. Depending from the lower portion'of the frame I M, are a pair .of lugs I28 constituting journal bearings for trotatably receiving a shaft I30 .extending longitudinally of the plate, which shaft at its extremities is provided with gears I32, each of these gears engaging a rack bar I34 rigidly secured in anysuitable manner to the frame Ill. These rack bars and gears provide guiding means for maintaining the parallel arrangement of the finger-assembly as the latter is adjusted laterally to and from the knife edge :26. Also extending rearwardly and integrally attached to thefitame I00, are a pair of tubular sleeves I36 (see Figure 4) constituting guide means which are slidably received in guide bores I 46 communicating with the interiorof the chamber 84. Coil springs 1-38 are positioned in the sleeves I 36, and abut against the inner surface of the rear wall I8, to yieldingly urge the finger assembly forwardly with respect to the knife edge 26 of .the. anvil .24.

' The fingers II 2 are positioned to be slidingly receivedin the notches T2, with the upperends H6 of the fingers pressed against .thelower surface of the anvil 24, and yieldingly urged thereagainst by the spring means LIB.

It will thus be seen that in both the ,forward position of the finger assembly, as shown in Figures 4 and 5, the notches '72, provide sufiicient clearance whereby themovable jaw 15 will not interfere with movement of the fingers while the latter will not prevent the closing movementAo'f the jaw. The adjusted position ofthe finger assembly rearwardly of the movable jawis s'hownin "Figure '8, where it will be seen that the .end

I 68 of the sheet metal strip I66 is abuttedagainst the front portion of the series of finger pins .I I6, while the upper surface of the .movable jaw clamps this marginal portion of the strip tightly against the undersurface of the anvil, while the rest of the strip is folded or bent around .the

knife edge 25 of the anvil.

It will be particularly noted that by reason of the notches 72, the stop finger assembly can be readily adjusted without necessitating any movement of themovable jaw 'HLif this isde- "sired; while in all positions of adjustment .of

the stop fingers, 'free operation of themovable jaw is permitted.

A'tliustczble fo'lderstop In order to-enable the operatorto readilyiorm of degrees ofa-rcuate-movement of the carriage, anadjustable stop mechanism is provided. This "mechanism as-in- 'dicated in Figure 2'and shown best in Figures 7 and :9, includes a lug 1'42 carried by one {of 19' the end walls [2 of the frame 10, which lug constitutes an abutment provided with an adjusting screw IM haVing a lock nut hit. A stop lug 1-48, adapted to engage the adjusting screw is carried by a collar I50 loosely received on the carriage-axle 32 between theboss 3i! andthe and bracket 36 of the carriage. -As indicated in dotted lines inFigure 7, thecollar lfifl is pro- .vided with a plurality of setsof diametrically opposite bores l 52 constituting locking recesses.

Ap airv of locking pins I55 carried by a locking pin l t '56 Prov de t a nse e ip k b 1.58, are slidably received withinand extend-through bores 159 formed in the member 36, and have their ends extensible intonthe locking recesses I52. A coil spring ltilsurrounds a stem Nil formedaxially on the platelet, the spring and stem being received in. aboreoriiaixial recess? l 62 formed in the end of the carriage axle $2. This spring is so positioned as to urge the plate I56 and the locking pins I54 into their inward or looking position as shown in Figure 9. In order to change the position of the collar I56 with respect to the carriage, and thereby change the position of the carriage when the movement of the same is limited by engagement of the lug I43 with the stop member M4; it is only necessary to withdraw the pins l54 against the opposition of spring lfiil to release the ends of the pins from the locking recesses I52, whereupon the collar I50 may be turned until another pair of recesses may be aligned with the pins. As will be readily understood, a plurality of these recesses will be provided, the relative positions of these recesses being such that any desired angular movement may be imparted to the carriage before the stops engage for limiting further movement. Thus, a series of the most frequent angular bends which it is desired to perform upon the machine may be readily attained by the easy use ofthe proper stop.

Referring now to Figure 5, by manipulation of the knob assembly may be retracted to permit a portion of the edge of a sheet of metal to be inserted between the jaw it and the anvil 24, the width of the margin so inserted being determined by the relative position of the stop finger assembly. One such position is shown in Figure 8, where it it will be seen that will be seen that this sheet 186 and its marginal edge I68 abutting the stop fingers H2, and the body portion of the sheet I66 has been fitted about the knife edge 26 by the upward movement of the holder bar as and carriage 34 to form a substantially perpendicular flange upon the sheet. Obviously this flange could be bent further until almost a complete 360 bend was effected, or until the folding stop was engaged.

From the foregoing, the construction, operation and advantages of the invention will be readily understood and further explanation is believed to be unnecessary. However, since numerous changes and modifications will readily occur to those skilled in this art after a consideration of the principles of the invention as set forth in the foregoing specification and annexed drawings, it is not intended to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the appended claims.

Having described the invention, as new is:

l. A sheet metal folder comprising a frame provided with an anvil having a metal bending what is claimed to said surface, a

I25, the stop finger "to" said frame, a

. movement of .said

' thereof for engagement surface, a movable jaw for clamping a metal sheet metal bending carriage pivoted I folder bar on said carriage, mechanism connecting said carriage and said movable jaw-for opening and closing movement of the latter. intimed-relation to movement of said carriage, rectilinear reciprocable latch means for said movable jaw and latch actuating means opto movement of said erable in timed relation including locking cams carriage, said latch means 'slidable beneath said movable jaw for preventing opening movement thereof, springs urging said cams into locking position, latch releasing bolts on said carriage, said bolts being positioned to release said latch means in timed relationto carriage and said movable jaw. 2; A sh'eet metal folder comprising a frame .provided with an anvil'having a metal bending surface, a movable jaw disposed beneath said an- -vil for clamping a metal sheet to said surface, a

metal bending carriage pivoted to said frame and having a folder bar thereon, resilient means urging said movable jaw towards said bending surface,-1atch wedge guides on said frame, latch Wedges mounted in said guides and slidable transversely of said movable jaw, latch surfaces on said movable jaw engageable by said latch wedges when the movable jaw has been urged towards said bending surface by said resilient means for locking said movable jaw in clamping position upon said bending surface, latch wedge retracting means on said carriage moving said Wedges out of engagement with said latch surfaces when said carriage is in its idle position and actuating means operable to move said movable jaw against said resilient means upon movement of said carriage away from said bending surface.

3. The combination of claim 2 wherein said wedge surfaces extend longitudinally of said frame and said latch wedges and guides extend transversely thereof. v

4. The combination of claim 2' wherein said wedge surfaces extend longitudinally of said frame and said latch wedges and guides extend transversely thereof, and are both disposedbelow the bottom of said movable jaw, said Wedges having actuating pins projecting beyond one end thereof for engagement by said retracting means. i 5. The combination of claim 2 wherein said wedge surfaces extend longitudinally of said frame and said latch wedges and guides extend transversely thereof, and are both disposed below the bottom of said movable jaw, said wedges having actuating pins projecting beyond one end thereof for engagement by said retracting means, a guide pin projecting beyond the other end of each wedge, guide means in said frame for each guide pin.

6. The combination of claim 2 wherein said wedge surfaces extend longitudinally of said frame and said latch wedges and guides extend transversely thereof, and are both disposed below the bottom of said movable jaw, said wedges having actuating pins projecting beyond one end by said retracting means, a guide pin projecting beyond the other end of each wedge, guide means in said frame for each guide pin, a spring surrounding each guide pin and urging its latch Wedge into latching position with its latch surface.

'7. The combination of claim 2 wherein said wedge surfaces extend longitudinally of said frame and said latch wedges and guides extend transversely thereof, and are both disposed below the bottom of said movable jaw, said wedges have ing actuating Joins nrojecting' beyond one end REFERENCES CITED The following references are of record in the file. of this patent: V 7

UNITED STATES PATENTS Number Name Date Re. 3,069' Stow Aug. 4, 1868 27,319 Stow Feb. 28', 1860 72,478 Gleason QDec. 24, 1867 362,749

Number Number 12 i Name- Date 'Stark Aug; 14, 1888 Reising Feb.'14,--1888 Koenig Apr. 3, 1888 Smith Mar. 19,1895 Schott Mar. 3, 1903 Keene Apr. 3, 1906 Talmadge May; 29, 1906 Benedek- Aug. 3, 1909 Stander Apr. 9,1912 Jarecki Nov. 11, 1930 Schaefer- Jan; 12, 1932 Warger Ju1y1'16,19%10 Babcock Mar. 7,1944 FOREIGN PATENTS Country- Date France Nov; 14, 1936 

